检索结果-南通市图书馆

Journal of Environmental Sciences 2017年第10期29卷 53-60页

作者： Mohamed Thabit Huiling Liu Jian Zhang Bing Wang state key laboratory of Urban Water Resource and Environment School of Municipal and Environmental EngineeringHarbin Institute of Technology School of Chemical Engineering Northeast Electric Power University

Pd-MnO2/TiO2 nanotube arrays（NTAs） photo-electrodes were successfully fabricated via anodization and electro deposition subsequently; the obtained Pd-MnO2/TiO2 NTAs photo electrodes were analyzed by scanning electron microscopy（SEM）, X-ray diffraction（XRD） and characterized accordingly. Moreover, the light harvesting and absorption properties were investigated via ultraviolet–visible diffuse reflectance spectrum（DRS）; photo degradation efficiency was investigated via analyzing the photo catalytic degradation of Rhodamine B under visible illumination（xenon light）. The performed analyses illustrated that Pd-MnO2 codoped particles were successfully deposited onto the surface of the TiO2 nanotube arrays;DRS results showed significant improvement in visible light absorption which was between400 and 700 nm. Finally, the photo catalytic degradation efficiency results of the designated organic pollutant（Rhodamine B） illustrated a superior photocatalytic（PC） efficiency of approximately 95% compared to the bare TiO2 NTAs, which only exhibited a photo catalytic degradation efficiency of approximately 61%, thus it indicated the significant enhancement of the light absorption properties of fabricated photo electrodes and their yield of UOH radicals.

关键词： Pd-MnO2/TiO2 Nanotubes Photo electrode Photo degradation Rhodamine B Photo-catalytic efficiency

Hydraulic Accumulator-Motor-Generator Energy Regeneration system for a Hybrid Hydraulic Excavator

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2012年第6期25卷 1121-1129页

作者： LIN Tianliang WANG Qingfeng state key laboratory of Fluid power Transmission and Control Zhejiang University Hangzhou 310027 China College of Mechanical Engineering and Automation Huaqiao University Xiamen 361021 China

Though the traditional energy regeneration system（ERS） which used a hydraulic motor and a generator in hybrid excavators can regenerate part of the energy, the power of the motor and the generator should be larger and the time for regenerating energy is so short. At first, the structure of new ERS that combines the advantages of an electric and hydraulic accumulator is analyzed. The energy can be converted into both the electric energy and the hydraulic energy at the lowering of the boom and the generator can still works when the boom stops going down. Then, a method how to set the working pressure of the hydraulic accumulator is proposed. To avoid the excess loss, extra noise and shock pressure, a two-level pressure threshold method that the generator starts to work at the rising edge of the high pressure threshold and stops working at the falling edge of the low pressure threshold is presented to characterize the working mode of the generator. The control strategies on how to control the boom velocity at the lowering of the boom and how to improve the recovery efficiency when the boom stops going down are presented. The test bench of hybrid excavator with ERS is constructed, with which the studies on the influences of ERS on energy conversion efficiency and control performance are carried out. Experimental results show that the proposed ERS features better speed control performance of the boom than traditional ERS. It is also observed that an estimated 45% of the total potential energy could be regenerated at the lowering of the boom in the proposed ERS, and the power level of the generator and the hydraulic motor could be reduced by 60%. Hence, the proposed ERS has obvious advantages over the traditional ERS on the improvement of energy regeneration time, energy efficiency, control performance and economy.

关键词： hybrid system excavator energy regeneration system energy-saving

Optical modulation of repaired damage site on fused silica produced by CO2 laser rapid ablation mitigation

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2020年第5期29卷 288-296页

作者： Chao Tan Lin-Jie Zhao Ming-Jun Chen Jian Cheng Zhao-Yang Yin Qi Liu Hao Yang Wei Liao state key laboratory of Robotics and system Harbin Institute of TechnologyHarbin 150001China Research Center of Laser Fusion China Academy of Engineering PhysicsMianyang 621900China

CO2 laser rapid ablation mitigation(RAM)of fused silica has been used in high-power laser systems owing to its advantages of high efficiency,and ease of implementing batch and automated *** order to study the effect of repaired morphology of RAM on laser modulation and to improve laser damage threshold of optics,an finite element method(FEM)mathematical model of 351 nm laser irradiating fused silica optics is developed based on Maxwell electromagnetic field equations,to explore the 3D near-field light intensity distribution inside optics with repaired site on its *** influences of the cone angle and the size of the repaired site on incident laser modulation are studied as *** results have shown that for the repaired site with a cone angle of 73.3°,the light intensity distribution has obvious three-dimensional *** relative light intensity on z-section has a circularly distribution,and the radius of the annular intensification zone increases with the decrease of *** the distribution of maximum relative light intensity on y-section is parabolical with the increase of *** the cone angle of the repaired site decreases,the effect of the repaired surface on light modulation becomes stronger,leading to a weak resistance to laser ***,the large size repaired site would also reduce the laser damage ***,a repaired site with a larger cone angle and smaller size is preferred in practical CO2 laser repairing of surface *** work will provide theoretical guidance for the design of repaired surface topography,as well as the improvement of RAM process.

关键词： fused silica laser repaired surface optical modulation finite element method(FEM)

面向个性化健康管理的柔性自供能生物诊疗电子器件

在线全文

学校读者我要写书评

暂无评论

Science Bulletin 2024年第14期69卷 2289-2306页

作者：姚光甘兴羿林媛 School of Materials and Energy University of Electronic Science and Technology of ChinaChengdu 610054China state key laboratory of Electronic Thin Films and Integrated Devices University of Electronic Science and Technology of ChinaChengdu 610054China Shenzhen Institute for Advanced Study University of Electronic Science and Technology of ChinaShenzhen 518110China Medico-Engineering Cooperation on Applied Medicine Research Center University of Electronic Science and Technology of ChinaChengdu 610054China

Flexible self-powered bioelectronics(FSPBs),incorporating flexible electronic features in biomedical applications,have revolutionized the human–machine interface since they hold the potential to offer natural and seamless human interactions while overcoming the limitations of battery-dependent power ***,as biosensors or actuators,FSPBs can dynamically monitor physiological signals to reveal real-time health abnormalities and provide timely and precise ***,FSPBs are increasingly shaping the landscape of health monitoring and disease treatment,weaving a sophisticated and personalized bond between humans and health ***,we examine the recent advanced progress of FSPBs in developing working mechanisms,design strategies,and structural configurations toward personalized health management,emphasizing its role in clinical medical scenarios from biophysical/biochemical sensors for sensing diagnosis to robust/biodegradable actuators for intervention *** perspectives on the challenges and opportunities in emerging multifunctional FSPBs for the next-generation health management systems are also forecasted.

关键词： Flexible bioelectronics Self-powered Sensing diagnosis Intervention therapy Health management

Experimental investigation of the full coverage film cooling effectiveness of a turbine blade with shaped holes

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2022年第3期35卷 297-308页

作者： Cunliang LIU Fan ZHANG Shuaiqi ZHANG Qingqing SHI Hui SONG School of power and Energy Northwestern Polytechnical UniversityXi'an 710129China Shaanxi key laboratory of Thermal Sciences in Aero-engine system Xi'an 710129China Beijing Institute of Radio Measurement Beijing 100854China

The film cooling effectiveness of two turbine blades at different turbulence intensities(0.62%and 16.00%)and mass flux ratios(2.91%,5.82%,8.73%and 11.63%)is studied by using the Pressure-Sensitive Paint(PSP)measurement *** are a baseline and an improved turbine blade in current work,and their film cooling hole position distribution is the *** the hole shape on suction surface and pressure surface is changed from cylindrical hole(baseline)to laid-back fan-shaped hole(improved blade).Both blades have 5 rows of cylindrical holes at the leading edge and 4 rows of cooling-holes on the suction surface and the pressure *** experimental results show that the film cooling effectiveness of the improved blade is much better than the *** increase in turbulence intensity will reduce the cooling effectiveness on the surface of turbine blade,but the effect of turbulence intensity becomes weaker with an increase in the mass flux *** with the multiple rows of cylindrical holes,the cooling effectiveness of shaped holes is more influenced by the turbulence intensity at low mass flux ratio.

关键词： Adiabatic film cooling effectiveness Film cooling Shaped holes Turbine blade Turbulence intensity

Preliminary estimation of the organic carbon pool in China's wetlands

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2013年第2期58卷 662-670页

作者： ZHENG YaoMin NIU ZhenGuo GONG Peng DAI YongJiu SHANGGUAN Wei state key laboratory of Remote Sensing Science Jointly Sponsored by Institute of Remote Sensing ApplicationsChinese Academy Sciences and Beijing Normal University Ministry of Education key laboratory for Earth system Modeling Center for Earth System ScienceInstitute for Global Change StudiesTsinghua University Department of Environmental Science Policy and ManagementUniversity of California College of Global Change and Earth system Science Beijing Normal University

Accurate estimation of wetland carbon pools is a prerequisite for wetland resource conservation and implementation of carbon sink enhancement *** inventory approach is a realistic method for estimating the organic carbon pool in China's wetlands at the national *** updated data and inventory approach were used to estimate the amount of organic carbon stored in China's *** results are as follows:(1) the organic carbon pool of China's wetlands is between 5.39 and 7.25 Pg,accounting for 1.3%-3.5% of the global level;(2) the estimated values and percentages of the organic carbon contained in the soil,water and vegetation pools in China's wetlands are 5.04-6.19 Pg and 85.4%-93.5%,0.22-0.56 Pg and 4.1%-7.7%,0.13-0.50 Pg and 2.4%-6.9%,*** soil organic carbon pool of China's wetlands is greater than our previous estimate of 3.67 Pg,but is lower than other previous estimates of 12.20 and 8-10 *** on the discussion and uncertainty analysis,some research areas worthy of future attention are presented.

关键词：土壤有机碳库湿地资源中国估算不确定性分析模估计交流计数湿地土壤

Navigable flow condition simulation based on two-dimensional hydrodynamic parallel model

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2018年第4期30卷 632-641页

作者：张尚弘吴昱荆柱易雨君 Renewable Energy School North China Electric Power University state key laboratory of Water Environment Simulation and Pollution Control School of Environment Beijing Normal University

Navigable flow condition simulations can provide detailed information on water depth and velocity distribution, simulation speed is one of the key factors which influence real-time navigation. In this paper, a navigable flow condition simulation system is developed to provide useful information for waterway management and shipping safety. To improve the simulation speed of 2-D hydrodynamic model, an explicit finite volume method and Open MP are used to realize parallel computing. Two mesh schemes and two computing platforms are adopted to study the parallel model＇s performance in the Yangtze River, China. The results show that the parallel model achieves dramatic acceleration, with a maximum speedup ratio of 34.94？. The parallel model can determine the flow state of the navigable channel in about 4 min, efficiency is further improved by a flow simulation scheme database. The developed system can provide early warning information for shipping safety, allowing ships to choose better routes and navigation areas according to real-time navigable flow conditions.

关键词： 2-D hydrodynamic model finite volume method parallel computation OpenMP navigable flow condition

Development of an electric control gas-tight sampler for seafloor hydrothermal fluids

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2014年第2期15卷 120-129页

作者： Shi-jun WU Can-jun YANG Hao-cai HUANG Ying CHEN state key laboratory of Fluid power Transmission and Control Zhejiang University Hangzhou 310027 China Department of Ocean Science and Engineering Zhejiang University Hangzhou 310027 China

Submarine hydrothermal vents occur over a wide depth range from a few meters to several thousands of meters. Most existing hydrothermal fluid samplers are focused on deep-sea environments and are not suited for collecting shallow-water fluids. In this study, a new gas-tight sampler which can be easily deployed by both submersibles and scuba divers to collect fluid samples from both deep-sea and shallow-water hydrothermal vents is presented. The proposed sampler uses an electric control sampling valve for fluid collection and a system to measure and display the temperature of the hydrothermal fluid while sampling. It is capable of working in manual mode to be controlled via external signals, or in automatic mode to collect a fluid sample according to the temperature. The master-slave architecture of the electronic system makes the sampler flexible in meeting many different deployment requirements. The performance of the sampler has been demonstrated by preliminary field tests at a shallow-water hydrothermal vent site.

关键词： Hydrothermal fluid Electric control Sampler Deep sea Gas-tight

In-flight performance analysis of the navigation augmentation payload on LEO communication satellite:a preliminary study on WT01 mission

在线全文

学校读者我要写书评

暂无评论

Geo-Spatial Information Science 2022年第1期25卷 88-103页

作者： Ziqian Wu Baoguo Yu Chuanzhen Sheng Jingkui Zhang Song Xie Cailun Wu state key laboratory of Satellite Navigation system and Equipment Technology ShijiazhuangChina The 54th Research Institute of China Electronics Technology Group Corporation ShijiazhuangChina

With the development of the Low Earth Orbit(LEO)communication constellations,it has become a hot area of research to provide additional navigation augmentation *** by volume,weight,power consumption,and running time,the in-flight performance of navigation augmentation payload remains to be *** this paper,we analyze the data quality of on-board GNSS observation and evaluate the precision of short-arc dynamic Precise Orbit Determination(POD)performance based on the WangTong-01(WT01)***,the downlink navigation measurement data of WT01 satellites are analyzed and compared with the GNSS *** results show that the average multipath errors of the WT01 on-board GPS L1,L2 and BeiDou Satellite Navigation system(BDS)B1,B2 code observation are 0.54,0.74,0.65,and 0.58 m,*** short-arc dynamic POD three-dimensional(3D)overlapping accuracy is 7.1 *** average multipath errors of downlink navigation signal Z1 and Z2 are 0.81 and 0.80 m,respectively,which at the same order of magnitude as GNSS *** maximum Carrier-to-Noise Ratio(C/N0)value of WT01 downlink measurement data can reach 60 dB Hz,which is much stronger than GNSS and indicates the navigation signals of LEO satellites can meet the basic requirement of navigation augmentation.

关键词： Navigation payload in-flight performance augmentation communication satellites LEO

A theoretical and 1-D numerical investigation on a valve/valveless air-breathing pulse detonation engine

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2021年第1期34卷 68-78页

作者： Hua QIU Cha XIONG Jianling LI School of power and Energy Northwestern Polytechnical UniversityXi'an 710072China state key laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China

The important operating characteristics of pulsed Pressure Gain Combustion(PGC)propulsion are the pressure gain of the combustor component and the propulsive performance gain of the engine.A ramjet-type valve/valveless air-breathing pulsed detonation engine with a supersonic internal compression inlet is *** on an ideal thermal cycle,the ideal equivalent pressure ratios(pcb)of the Pulsed Detonation Combustor(PDC)are obtained theoretically which are directly related with the propulsive performance of the *** introducing an orifice loss model into the cycles,the critical pressure drop ratios through the orifice for the PDC achieving pressure gain and the engine achieving thrust gain are *** influencing factors are investigated by the use of a one-dimensional(1-D)numerical simulation *** operating characteristics of the pulse detonation engine are investigated with changes of the valve type,the inlet/outlet area ratio of the PDC,the nozzle area ratio,and flight *** these factors can affect pcbof the PDC,and pcbcan be optimized by changing the geometry of the *** most important influence parameter is the valve *** using an orifice-type aerodynamic valve,simulation results show that the PDC cannot achieve the pressure gain *** a supersonic internal compression inlet is introduced to the engine,whether the Pulse Detonation Engine(PDE)can achieve thrust gain comparable with that of an ideal Brayton cycle engine not only is related to the pressure gain of the combustor,but also needs to optimize the engine structure to reduce the total pressure loss.

关键词： Detonation Pressure gain characteristics Propulsive performance Supersonic internal compression inlet Valve/valveless Thermal cycle